Our hypothesis is that gliomatosis cerebri is a distinct entity that has chromosomal abnormalities that are common to GC and chromosomal abnormalities that overlap with abnormalities seen in other gliomas. In our study, we hope to identify copy-number aberrations that correlate with the more common characteristics of this tumor type. We shall use array CGH to determine copy-number aberrations and to map them directly onto the human genome sequence. Array CGH will allow us to determine the copy number of amplified and deleted areas of the genome and the chromosomal locations of these abnormalities at a resolution of about 1 megabase. After determining locations of copy-number aberrations, we shall compare these aberrations statistically among individuals to find areas of the genome with frequent copy-number aberrations in GC. We shall use this data to determine if there are specific patterns of chromosome aberrations that are characteristic of GC. Our final goal is to compare copy-number aberrations seen in GC to those seen in other non-GC astrocytic tumors. [unreadable] [unreadable]